Undervolting 3600

Rockbox · 11 Mar 2022 at 00:34

Like my GPU, I want to undervolt my kit to stock settings with lower voltage. Glancing at my Vcore, it seems to be 1.4x with PBO and autoOC. It was quieter and probably cooler a month ago before I enabled that stuff, and I'm not seeing much improvement.

Using RyzenMaster, I capped the vcore to 1.325, which it was stuck at, then 1.35, which it seems to hover below. I set my best and 2nd best cores to 4.2, and the others to 4.1. 4 of my cores are stuck at 4.2, while the other two are at 3.36ghz, This is at both vcores.

I was getting around 4.1 all core before at the 1.4x voltage. Is 3.36 on my weakest cores the price to pay? I tried going to 4.3, but it crashed. Am I better off with PBO and autoOC on? Not bothered about longevity, as the 3600 doesn't seem excellent for gaming, and while undervolts seem to not affect average fps much, I care more about 1% lows, which according to an article about Ryzen in eco mode, seem to be affected.

Rockbox · 11 Mar 2022 at 01:24

PBO and Auto OC, at least on Zen 2, seem to be useless. "Normal" causes the CPU to hang below 1.4v, while "Auto OC" causes it to hang above that. All for a 5fps difference in the minimum, and 1 fps in the average and maximum of the game I benchmarked.

It has a measurable effect, but reminds me of those game booster programs I used on my laptop during the core 2 duo and 9600m gt days. They taught me that the only real way to improve performance was through better hardware.

Joxeon · 11 Mar 2022 at 08:09

Did you try manual overclocking? Set vcore to overide mode 1.3v and then set the core clock to 4ghz and up it till it's no longer stable, most decent chips should do 4.2 @1.3v.

Rockbox said:
ster, I capped the vcore to 1.325, which it was stuck at, then 1.35, which it seems to hover below. I set my best and 2nd best cores to 4.2, and the others to 4.1. 4 of my cores are stuck at 4.2, while the other two are at 3.36ghz, This is at both vcores.

If you try per core OC then some of the cores will run at the base level despite setting higher, if you go in the bios you can do per CCX, each CCX comprises of 3 cores so you could set 1 to 4.1 and the other to 4.2 etc.

Rockbox · 11 Mar 2022 at 08:56

The Vcore in Override mode, do I do that in the Bios or Ryzen Master? I have a B450i Aorus Pro, and the options of CPU Vcore and Vcore SOC. Dynamic Vcore and Dynamic Vcore SOC are greyed out, and typing "normal" in the settings for CPU Vcore and Vcore SOC didn't unlock them.

I used to use voltage offsets on an Intel Z77, but I read that offsets are the same or worse. If I set to 1.3, will the cpu always run at 1.3, even when idle?

Also, something I'm confused by. Does the chip ever drop below the frequency of 3.6ghz? I mean to 2 or 1. Because I seem to have mistaken utilisation for frequency.

Joxeon · 11 Mar 2022 at 14:06

Set the vcore to overide in the bios and set 1.3, the SOC is for the memory controller and can be left on auto.

If you set 1.3 the CPU will always run 1.3 unless you put it under heavy load where Vdroop will kick in depending on the level of load line calibration you have set, level 4 load line is fine as you generally want some Vdroop.

3.6 is the base frequency so the CPU shouldn't drop below this, if you manually configure the clocks to say 4.0ghz then the CPU will sit at this although cores will still enter sleep state even with all core OC.

Rockbox · 11 Mar 2022 at 14:52

OK. I set the vcore to 1.3 in the bios. RyzenMaster and Coretemp are showing it as 1.1 in their programs. Does that mean the 1.4x it was hitting on "auto" was closer to 1.6x?

I wanted to ask about Windows preferred core not being the fastest core in the system, but I read an Anandtech article on it saying it's no big deal.

Do I lose anything sticking to 1.3 and 4ghz? Does "auto" go below 1.3 for light work loads like web browsing, in ways which might add up in terms of power?

If it's OK to be at 4ghz (to start) all the time, what's the point of a boost clock? Why not have a higher boost that drops when necessary, as I thought running at 4 constantly would affect power?

Joxeon · 11 Mar 2022 at 19:06

I'd probably shoot for atleast 4.2 then you don't lose out on any single core boost, my sample needed needed 1.325v to do 4.2 but temps were still 8c cooler than stock where it would only boost to 4ghz.

Rockbox · 11 Mar 2022 at 20:38

Seems I have an absolute basement-tier chip that needs 1.325 just to do 4.1. (edit:spoke too soon). Goes with my basement-tier ram that won't move an inch in timings.

Haven't done benchmarks, but I get this weird hitching and stuttering in the game I test with. Not sure if 1% lows are worse, or the chip isn't getting enough power.

Whats's the difference between eco mode and 4ghz @ 1.3? I feel like that's my chip's sweet spot, unless I start ccx overclocking.

Rockbox · 12 Mar 2022 at 00:00

This is what I managed to get it down to. And by "get down" I mean booting to Windows without bluescreening and running a benchmark.

1.275 | 4ghz all core (not properly tuned)

1.3 | 4ghz (actually played some games on - stable)

1.35 | 4.1/4.0

1.375 | 4.15/4.175

1.39 | 4.15/4.2

Funnily enough, the ccx with the best core doesn't clock as high.

Vdroop set to "high", It's absurd how much extra voltage is needed for these tiny clock boosts.

Might stick to 1.375, but given I can drop 100mw for not even 5% underclock, it brings me back to my dilemma of diminishing returns in terms of performance.